The COVID-19 pandemic started with the first known cases of an unusual pneumonia in Wuhan, China, identified around December 2019. The World Health Organization (WHO) was informed about this cluster of cases on December 31, 2019. The virus, later named SARS-CoV-2, was officially recognized in early January 2020. The first confirmed case in the U.S. was reported in January 2020, and by March 2020, the WHO declared COVID-19 a global pandemic. The pandemic's public health emergency status ended in May 2023.
